I think one of the most interesting things in the latest chapter waste recon team from Irwin. Why were they in LA? What was the purpose of the "map"? I have a theory.
I believe the maps are being gathered to aid Kimmet in planning an attack on LA. He needs intelligence on infrastructure and zombie movement and concentrations. I think he has enough intel to identify LA as the source of the infection.(at least on the west coast) I think he has the means and intention to pinpoint the source and destroy it, allowing him to re-claim whatever part of the city remains. I know there has been some discussion about a nuke. I don't think that is the weapon he has access to however I do believe it is something he feels will get the job done. In addition, I think he is willing to accept a high level of civilian casualties to accomplish this. I could see this leading to conflict with Michael and making the story at Irwin quite interesting. This could also complicate the rescue Lizzy/Mallers at the colony storyline.